Telephone-receiver.



W. H. THOMPSON da H. R. STUART.

TELEPHONE RECEIVER. APPLICATION IILED JUNE 11, 190e.'

Patented me. 27, 1910.

2 SHBETHSHEET 1.

W. TI. vTHOMPSON &' H. R. STUART.

TELEPHONE RECEIVER.

APPLIOATION FILED JUNE 11, 1909.

Patented Dec. 27,1910

2 SHEETS-SHEET 5 wu@ www If/LBUI? H. THOMPSON i/MIMMO: y I i l.

.WIL-BUn-rnnnoivrrson, or WE1/snuiven, weer VIRGINIA, Ann nani/n nnsmnnnr; or

i sa rio MILWAKEE; Wisconsin.

T o all whom it may concer/AL:l

Be it known that we, WILBUR H..TH'oMP son and HARvn R. STUART, citizens of the United States, residing, respectively, at'= Vheeling, county of' 0hio, and vState of Vilest Virginia, and' plntilwaukee, inthe county bf Milwaukee and State of Wisconsin, haveinvented certain new and useful' Improvements in Telephone-Receiveis of which the following is full, clear, and exact description.

This invention relates to telephone ref ceivers, particularly for use in telegraphones, where only light operatingl ifui'rents are available, and where a"clcar sound reproduction is important. i

A type of receiver has hitherto beenV pro- "posed making use of' a. solenoid coil inplace of a magnet bobbin, the solenoid coil acting to vary the intensity oi? a pair of juxtaposed' magnetic poles which are caused to be pro. duced within the interior ot the solenoid.

The present .invention relates to this general type of apparatus and includes a 'va-- riety oi' iteatnresfbywhich a more simple and efficient construction` is provided, and in whic`-` all of the parts are very strongly and compactly arranged and` organized together.

Among other features the present invention makes use of two receivers compounded 'into one, and which are joined in separate circuits from the separat-e magnets of atelcgraplione, 'sons to operate entirely independently of one another. The result is that any slight differences in phasel between the voice or telephonie currents from the vseparate telegraphone magnets cannot :ct at any time to neutralize or interfere wit lone another. IEach is independently transformed into sound Waves, and if these vary slightly'in phase it is immaterial, especially as they are led through separate tubes to the operating with two separate solenoids with Specification oi? Letters Patent. i Pagnted Da, 2*?, Application :tiled J" une l1; 1509. "Serial No. 50?.,493.

vseparate diaphragme, thereby providdng.4 in

eecta double receiver. l/Vith these 'various and other objects in View our invention consists inA the features' 60 of construction and combination as herein'- after set toifth and claimed.

In the drawings; Figure l is a perspefz-` tive'view illustrating the appearance and use of a telegraphone receiver embodying the principles ot' our invention; Fig. 2 is al plan view of the receiver; Fig. 3 'is a similar'.` view with some oi' the parts removed; Fig.- et is a transverse sectional view o n the line lV-V of Fig. 2, and Fig. 5 s a sectional |70 viewfon the line Y-Vof Fig. 2; 6 a

lviewlsiinilar to Fig. 3 'showing the 'di'apliragm support in place; Fig. 7 -is,a side "elevation of the diaphragm; Fig.' 8 is a front View 'of the sameg-Fig. 9 is afdi'a- 7 5y gramXot' the circuits. v

Referringto the drawings 1n which like parts are designated by the same reference sign, l denotesa box or casing forming the le make this box of frame of the receiver. oval or elongated outline with flat top and bottom faces. i y A 3 denotes a permanent magnetwithin the box or casing I and which is also of" oval` outline, closely' fitting the interior of the boitv 85 around its entire .inner wall.' This magnet is preterablyot tlie'compound`type built up of the superposed plates, each magnetized rto produce consequent poles on a middle die ameter of the oval outline, corresponding to 9D- the points 4t and vof Fig. 3.'

6 denotes a .forked soft iron stamping, which is securedto the magnet 3 on the underside thereof at the point 4, and 7 denotesA l a similar forked soft iron stamping which is attached to the other pole 5 on the upper faceot theinagnet These forked pieces 6 and T, respectively constitute bifurcated poles or pole pieces of the magnet 3. Any convenient means may be employed for se- 100 curing these bifurcated poles 'in place, but

we prefer to make use of rigid studs 9, 9

which are iixedto the bottom Wall l0 of the 'casing 1. These studs are .best made of soft iron so as to lead the magnetic iiux as-elicientl-y as possible from the various layers of the magnet 3 to the bifurcated poles 6, 7. The bifurc'ated pole pieces 6,' 7, project so that their respective' extremities liev over one another centrally in the round open spaces at 11@ the ends of the interior oval outline of the magnet 3. At these locations there are also 15 by which these screws areturned' and adjusted through aboutl half a turn corresponding to a minutelpngitudinal displacement. The arms or Ahandles 18 can be screwed into various holes 19in-the heads of the screws whereby the screws can be initially set at any location desired, and

thereafter made adjustable through a limited distance corresponding to the-half turn movements of the arms 18.

20 denotes spring clips orwasher's which are fixed beneaththe heads of the screws 15 and which 'bear against the bottom face 10 j, of the box 1, so as to take up any back lash or lcoseness in the screws. These screws4 constitute extensions of 'the lower pole piece 6. As will later appear wev also provide/ what are virtually corresponding extremities of the upper pole piece 7.

At the front or open face ofthe box l, we provide a lplatef22 yconstituting a diaphragm support.l This plate has two lar e perfora# tions or openings 23V coaxial-wit the solenoids12.- f y 24 denotes' diaphragms supported over the openings`23- and each having a central soft lron studv 25 whichl projectsintothe interior of the corresponding solenoids 12. vEach ofv thesey studs 25 is small enough to enter looselyzthrough the aperture l13o-f the upper bifurcated pole 7 and islong enough to reach into very close proximity .to'theinner end of the corresponding screw"I 15..` These 'studs therefore constitute the extensions of the upper pole iece 7 which have beenpreviously referred) to As a practical feature v of construction we make the diaphragme 24 of'very thin metal with a thickened portion or strengthening washer 26 at the middle.'

thereof, whichnot only establishes a irnr anchorage for the stud 25, but a'lso'transmits .the movement of the st ud tov a wider' area of the diaphragm, thereby obtaining a more eiii'cient sound reproduction from a given;

v'degree of movement of said stud..- 'The diaphra'gms 24a-are. clamped against. their sup'- x porting plate `2 2 by a" cover 28 which'has outwardly coned or embossed portions 30 --overithe area of -the vworking. or vibrating pf'ntions of thej -diapliragms to permit theiry Cfr ee movement. 32 denotes tubes extending outwardjfrom the centers of these embossed areas 30 and"to"which the usual rubberl or liexible tubesfdinay be connected. f

. eso,

.The electrical connections are made by` a flexible cord 35 having three conductors which may be joined to the tip, ring and` dinary telegraphone, it is evident that en t-irely separate'circuit connections may be made therefrom to the separate coils 12 by the use of this simple three wire circuit.

The foregoing receiver is designed to be supported by a neckv strap or band designed `to be placed around the neck of the operator and bearing suitable meansl forv engaging the key-hole slot 47v of the receiver.

45 denotes" a/ plate fixed to the block 140 on the underside of the receiver and having an angularly bent ear 46 with an inverted keyhole slot A47 therein. The plate 45 has rounded 'extremities48 coaxial in their' curvature to the movement of the arms 18.

In this way'only the tip of the arm 18 is 4 exposed for mani ulation, 'and the interior parts are protect from exposure and from being tampered with. Thereceiver tubes 82 project upward f and are conveniently exposed for' the attachmentof `therfiexible' tubes 33. AThe operation of the receiver is as follows: The magnet 3 impels a strong field or flux Athrough the interiors of both the.

solenoids 12, this field beingled in this man ner'by the bifurcated poles 6 and 7, and the `screws and studs 14 and 25. 'The only appreciable air gapin the circuit" isthat between the adjacent ends of these screws and'. studs, and this gap is adapted tobe adjusted as already described.g Thevariations in the magnetization of the solenoids due to tele* phonic currents .produce corresponding variations in vthe attraction between the proximate poles which'are vformed at the adjacent extremities of said screws and said studs. These vvariations are directly/.transmitted to the diaphragms 24 and ergylthat is available in telephoniccurnentl magnet, a pair 4of separate coils and diaphragms associated therewith,` separate reduce a sound reproduction which has a most all the e111-A sound receiving' and carrying tubes for said diaphragme;- said tubes being"extended to.

j'iernuit the free ends; thereof to be posi# tioned. one adjacent each ear of the person `using the receiver, and said connections comphonic currents in said separate circuits.

separate diaphragms actuated by the varysaid solenoids into close proximity to one prising separate circuits for energizing said coils, such circuits being independently energizable,; the aforesaid elements coperating to obviate the neutralizing eifect of slight differencesv in phase between 'tele- 2. In a telephone receiver, an oval permanent vmagnet having consequent poles, a pair of bifurcated' pole pieces projecting from said poles, a pair of solenoids joining the extremities of the respective pole pieces, extensions from said pole pieces entering said solenoids into close proximity to one another, anddiaphragms actuated by the varying attraction between said extensions.

3. In a telephone receiver, a permanent magnet, a pair, of solenoids, pole piece extensions projecting from said magnet` into close proximity to each other, said extensions being inwardly directed into said solenoids, means for independently adjusting extensions in separate solenoids, and

ing attraction between said extensions.

et. In a telephone receiver, an oval per- 'manent magnet having consequent poles, a pair of vbifurcated pole pieces projecting from said poles, a pair of solenoids joining the extremities of the respective pole pieces, extensions from said pole' pieces entering another, diaphragms actuated by the varying attraction between said extensions, and separate circuits for said coils.

' 5. In a telephone receiver, an oval permanent magnet'iaving consequent poles, a pair ot' bifurcated pole pieces projecting from said poles` a pair of solenoids joining the cxtremities of the respective pole pieces, ex-. tensions from said pole pieces entering said solenoids into close proximity to one anmagnet, a pair of'bifurcated pole pieces projecting from the poles thereof, a pair of solenoids disposed adjacentl the respective .pole-pieces, pole piece extensions 1n said solenoids, and diaphragm parts actuated by the .varying magnetic ux in said exten- Y sions.

7. In a telephone receiver, a magnet, a plurality of bifurcated pole pieces projecting from the poles-thereof, a plurality of solenoids disposed adjacent the respective pole pieces, pole piece extensions coperating with said solenoids, and diaphragm parts actuated by the varying magnetic iiux in said extensions.

8.- In a telephone receiver, a magnet, a plurality of solenoids, pole lpiece extensions projecting from said magnet into proximity to each other and coperating with .said solenoids, means for independently adjusting said extensions and diaphragms actuated by the varying magnetic flux` in said extensions. f

In Witness whereof,- We subscribe our signatures, in the presence of tWo witnesses.

VVVILBUR H.' THOMPSON. HARVE R. STUART.

Titnesses to signature of lVilbur I-I. Thompson f Louis WAL'rnns, W. E. BOWERS. W'itnesses to signature of Harve R. Stuart:

HERMINE Dnoxnnr, ITALTER REITMAN. 

